Pedigree data from recorded flocks are of importance for the proper flock management as well as for the selection programmes and accurate performance prediction. In this study we examined if the use of eight molecular markers and computer analysis package ATLAS can be applied to verify known pedigrees of Jezersko-Solčava and Improved Jezersko-Solčava sheep breed from Slovenia. 90.9 % of pedigree data were in concordance with molecular genetic tests whereas in four pedigrees discordant parentage tests were obtained. In two cases, a different father or mother was assigned, whereas in the other two pedigrees both parents were discordant with molecular test results. In the second part of this study we aimed to determine the paternity for four lambs of Istrian Pramenka breed, in which a random mating scheme with 20 rams was used and hence the lambs had no father assigned. Using the same set of eight microsatellite markers, we were able to unequivocally determine paternity for 3 out of 4 lambs. In one case the analysis was not informative enough but with inclusion of 4 more microsatellite markers its sire could be determined. With the chosen set of microsatellite markers and data analysis programme ATLAS it is therefore possible to efficiently perform pedigree data validation as well as paternity prediction for lambs from flocks, where a large number of rams are used in a random mating system. Applying such molecular tests could help sheep breeders in flock management and improve efficiency of selection programmes.